Alcohols, the syntheses of which are within the scope of the present invention, include hydroxycitronellol, 3,7-dimethyloctan-1-ol, and such ether alcohols as methoxy citronellol (7-methoxy-3,7-dimethyloctan-1-ol).
A primary use for hydroxycitronellol is as an intermediate in the synthesis of hydroxycitronellal, (7-hydroxy-3,7-dimethyloctan-1-al), a widely used perfumery material. Conventionally, in this synthesis, a mixture of geraniol and nerol is prepared from beta-pinene via myrcene hydrochloride and is partially hydrogenated to produce citronellol. Citronellol is then hydrated under acid conditions to produce hydroxycitronellol. It has also been made from myrcene by preparing the dihydrochloride and then chlorodihydrogeranyl acetate, followed by saponification and hydrogenation..sup.1 FNT 1. Perfume and Flavor Chemicals, Steffen Arctander, 1969, Vol. 1, 1737.
A primary problem with these routes to hydroxycitronellol is that they depend upon the availability of beta-pinene as a precursor for myrcene, and beta-pinene is in relatively short supply.
It is known to couple methylbutynol (3-methylbut-1-yn-3-ol) with certain allylic halides in an aqueous media in the presence of cuprous chloride and a base, the latter being either organic or inorganic. Yields range from 50 to 70% depending upon the allylic halide and the type of base used.
Methylbutynol, however, like all other acetylenes, has its own specific requirements for coupling. These are dependent on the nature of the particular coupling reactant, solvent employed, the method of forming the cuprous derivative, the presence of coordinating agents which can activate the cuprous acetylide, and many other factors. To Applicants' knowledge, no attempt has heretofore been made to couple methylbutynol with a compound such as isoprene chloroacetate (1-chloro-4-acetoxy-2-methyl-2-butene).
Copending application Ser. No. 560,550, filed Mar. 20, 1975 by William Oroshnik and Ralph E. Close, assigned to Assignee of the present application (identified as case No. I-1881) describes a process for the production of dehydrophytol and Vitamin E wherein hexahydropseudoionone is reacted with a metal acetylide in a condensation reaction to form the corresponding C.sub.15 acetylenic carbinol, which in turn through a series of reactions is coupled with isoprene chloroacetate to form a C.sub.20 acetoxy enyne. The latter by a further series of hydrogenation and saponification reactions forms the compound dehydrophytol. This in turn couples with trimethylhydroquinone to give dehydro-Vitamin E which is then hydrogenated to give Vitamin E. The disclosure of copending application Ser. No. 560,550 (case I-1881), is incorporated by reference herein.
In addition to the use of hydroxycitronellol as an intermediate for the production of hydroxycitronellal, the alcohol also is used in perfume compositions with the intention of stabilizing the hydroxycitronellal and prolonging the odor life of that aldehyde in compositions. The alcohol also has other uses.
Dimethyloctanol (3,7-dimethyloctan-1-ol) is also useful as an intermediate in the preparation of perfumery compositions and as an intermediate in the synthesis of juvenile hormones. Similarly, the ether derivatives of dimethyloctanol such as methoxy citronellol find use in the perfumery art and as intermediates in the synthesis of juvenile hormones.